1. Field of the Invention
The present invention relates in general to wall structures for nuclear reactor containment housings or pools and more specifically relates to such wall structures that include interconnected passages located inwardly of a liner for the pool and arranged to direct any leakage through the liner to a leak detecting zone.
2. Description of the Prior Art
The necessity for leak proof containment housings for radioactive materials is well known. Furthermore, it has also been recognized that even though much effort, care and expense is expended in building a containment housing, the possibility of structural leaks developing in the walls thereof cannot be totally eliminated. Consequently, wall structures have been developed for nuclear reactor containment housings to permit a detection of any structural leaks that may develop.
In U.S. Pat. No. 3,288,998, issued Nov. 29, 1966, a containment vessel is disclosed that includes a lining wall having an inner layer and an outer layer. The inner layer is formed from a smooth sheet metal material welded together to form a leak tight barrier. In contrast, the outer layer is formed of a sheet with a plurality of indentations, and the two layers are positioned together so that only the indentations of the outer layer contact the inner layer. Thus, a plurality of connected passages are defined by the two layers throughout the entire area of the lining wall. A pumpback compressor is connected to the passages for drawing air therefrom and supplying it to a radiation detector. Accordingly, when a leak in the lining wall develops, it can be immediately detected.
Although the above structure appears to provide a means for reducing the possibility of damage as the result of radioactive leaks, it has been found unnecessary to monitor the entire area of a lining wall since leaks only develop at the welds or fluid sealed connections of the members forming the liner wall. Accordingly, a need exists for a lining wall that provides for a monitoring of leaks only at the fluid sealed connection in such wall to enable a more effective detecting and localizing of leaks.